Process of smelting native-copper-bearing rock.



UNITED STATES Patented February '7, 1905.

'ATENT OFFICE.

FRANKLIN R. CARPENTER, OF DENVER, COLORADO.

SPECIFICATION forming part of Letters Patent No. 781,807, dated February'7, 1905.

Application filed January 23, 1903. Serial No. 140,222,

/b u lIf/MNJL it may concern:

Be it known that LFRANKLIN R. CARPENTER, a citizen of the United States,residing at Donver, in the county of Denver, State of U010- rado, haveinvented an Improved Process of Smelting Native-Oopper-Bearing Rock, ofwhich the following is a specification.

M y invention relates to the smelting of certain classes of orescontaining native or metallic copper, such as the conglomerate ores ofthe Lake Superior region.

Certain conglomerates yield alarge percentage of their copper contentsto the ordinary mechanical process of stamping and water concentration,because the copper is coarse; but others, like the Nonesuchconglomerate, carry copper so finely divided that all attempts atwinning it heretofore have signally failed. .lt has also been for a longtime recognized that the mechanical concentration universally employedon such deposits is incomplete, so that there is a loss of copper in thetailings. l have discovered, however, that such ores may be cheaply andeconomically treated by a smelting process that gives most excellentresults and which not only saves the finelydivided copper not heretoforesaved, but also the gold and silver often found in these rocks and lostby present processes. Even these beds like the Calumet and Hecla inaddition to the coarse copper carry some fine copper now lost in thetailing, as well as gold and silver, so that the process is applicableto all ores carrying native or metallic copper. These conglomerates areverysilicious, many of them essentially sandstones requiring if smeltedby ordinary smelting processes much iron flux; but 1 have found thatvery clean slags may be made with the use of limestone alone; but owingto the very small quantities of copper when compared with thelargequantity of slag formed it becomes necessary to add a carrier orcollector for the copper. 1 add, therefore, some sultid material, suchas iron pyrite, pyrrhotite, or copper pyrite or other sullid, whichcollects the linely-disseminated native copper by a reaction well known,but never before to my knowledge employed for this purpose. The metalliccopper unites with the sulfur-displacing iron and forms matte, which,having a greater specilic gravity than the slag, is easily separated insuitable settlcrs from it.

In the carrying out of my invention 1 use any ordinary blast-furnace,such as is now employed in the ordinary processes of smelting. 1 add tothe copper conglomerate a sul'licient quantity of limestone or otherbasic material and sufficient pyrite material to form a matte, chargingthe same with su flicient coke or charcoal into any suitableblast-furnace and smelting the same by application of a blast. There isformed in the furnace a very light slag and a very high grade matte, theformer free, or ncarlyso,from copper and the latter containing thecopper now in the form of sullid that for merly existed in theconglomerate in the free state. The sullid-bearing material to be addedto the furnace charge should be sullicient to theoretically satisfy thecopper; but the presence of an excess would be immaterial. The mattewhen separated from the slag may be subjected to any usual or desiredprocess for the recovery of values.

1 claim as my invention l. The process of smelting native-copperbearingrock which consists in smelting the same with a flux and sulfur,substantially as described.

2. The process of smelting native-copperbearing rock, which consists insmelting the same with a basic flux and sulfur, substantially asdescribed.

3. The process of smelting native-copperbearing rock which consists inadding thereto basic material, to form a slag and a sullid material toform a matte or carrier for the native copper and incidentally the goldand silver that may be present and smelting the mixture.

a. The process of smelting native-copperbearing rock which consists insmelting the same with lime and sulfur bearing material, substantiallyas described.

5. The process of smelting native-copperbcaring rock which consists inadding thereto basic and sullid materialsaml smelting the same to causethe basic material to unite with the rock to form a slag and the sulfurto unite with the copper to form a matte of greater specific gravitythan the slag.

6. The process of smelting native-copper- In testimony whereof I havehereunto subbearing r001 Which consists in adding thereto scribed myname. 25$: material and pyrltes and smeltmg the FRANKLIN R CARPENTER- 57. The process of smelting native-copper- \Vitnesses: I

bearing rock which consists in adding thereto 1. A. VENABLE, lime andiron pyrites and smelting the same. l GEO. K. HELDEN.

